Vigabatrin as add-on therapy for adult complex partial seizures: a double-blind, placebo-controlled multicentre study

Vigabatrin (VGB) is a novel antiepileptic drug effective as adjunctive ther apy in patients with partial seizures. In this study, the efficacy and tole rability of VGB as adjunctive therapy were evaluated in patients with refra ctory epilepsy. Adult patients with a definite diagnosis of complex partial seizures and/or partial seizures secondarily generalized were recruited from 10 Canadian c entres. Patients were randomized Co receive either active medication or pla cebo in a double- blind fashion and entered a 36-week titration and mainten ance phase with regularly scheduled visits. Both efficacy parameters and sa fety assessments were monitored. Clinical laboratory, evoked potential stud ies, MRI, and neuropsychological tests were also performed. Forty-eight percent of VGB-treated patients vs. 26 percent of placebo-treat ed patients had a 50 percent or greater reduction in the frequency of compl ex partial seizures and partial seizures secondarily generalized. Vigabatri n was well tolerated by the majority of patients. Minor neurological side e ffects were observed in a number of patients in both treatment groups. No s erious systemic toxicity was observed. No changes in evoked potential studi es or MRI findings were noted. Vigabatrin was found to be an effective and well-tolerated antiepileptic dr ug when used as adjunctive therapy in patients with difficult to control co mplex partial seizures and for partial seizures secondarily generalized. Vigabatrin is a selective irreversible inhibitor of the GABA- degradating e nzyme GABA transaminase(1-5) and has shown efficacy in a number of clinical trials in patients with difficult to control partial seizures. Vigabatrin has been found most effective against complex partial and secondarily gener alized tonic-clonic seizures in both adults and children(6-18). Vigabatrin has also been shown to reduce infantile spasms secondary to various aetiolo gies and is most effective in spasms associated with tuberous sclerosis(19) The aim of this study was to further extend the clinical experience with VG B as adjunctive therapy in the treatment of adult patients with difficult t o control complex partial seizures and/or partial seizures secondarily gene ralized In addition to the assessments of efficacy and tolerability to VGB, neuropsychological evaluations were also carried out. (C) 2000 BEA Trading Ltd.